Since the late 1970s, psychiatry has paid greater attention to rigorous diagnosis and classification, as evidenced by the 1980 publication of the then forward-thinking DSM-III (American Psychiatric Association 1980). Unlike earlier editions, DSM-III provided detailed diagnostic criteria and descriptive diagnoses. Subsequent editions, including DSM-III-R (American Psychiatric Association 1987) and DSM-IV (American Psychiatric Association 1994) (the text revision of which, DSM-IV-TR, was published in 2000; American Psychiatric Association 2000), refined these diagnostic criteria and made changes primarily on the basis of new empirical data and the results of field trials. Much of the attention to more rigorous nosology had been sparked by advances in the biology and treatment of various psychiatric disorders, making precise diagnosis ever more important. For example, the response to lithium carbonate of many patients diagnosed as having bipolar (manic-depressive) illness fostered diligent efforts to discriminate between manic-depressive illness and schizophrenia, which resulted in a change of diagnosis for many patients and alterations in their treatment.